I spray them with an exterior Spar Urethane made by Rust-Oleum. It is suppose to sea our water.
I have started my next one and have drawn a different flag on another one. So now as one is drying, I can start painting on another. I am working on them hot and heavy now cause when the weather warms up, all my time will be spent cleaning up my gardens and flower beds and then planting veggies.